In U.S. Pat. No. 3,919,353 compositions based on saturated polyesters have been disclosed and claimed, the shock resistance of which was enhanced by dispersing into them an elastomeric phase constituted by butadiene rubbers, such as, e.g., polybutadiene or butadiene/styrene copolymers, or by polyolefinic rubbers, such as, e.g., saturated or unsaturated ethylene/propylene copolymers, which have been previously cross-linked and modified by a grafting reaction with polar monomers. In the grafted and cross-linked elastomer, the cross-linked phase is present in an amount of at least 30%, and, preferably, at least 50%.
The shock resistance of such compositions, at room temperature, is considerably improved as compared to that of polyesters without such an elastomeric phase; however, their low-temperature shock resistance, in particular within the range of from 0.degree. C. to -40.degree. C., is not completely satisfactory for some applications.
New shock-resistant, polyester-based compositions have been now discovered, in accordance with the present invention, which maintain high characteristics of shock resistance also at low temperatures.